Mercedes

Have Mercedes questions? Ask a mechanic for answers ASAP

Ask an Expert,
Get an Answer ASAP!

Fuel pressure is low, only 45, 200k, mlJA: Are you fixing…

Customer Question
Fuel pressure is low...

Fuel pressure is low, only 45

Mechanic's Assistant: How many miles are on the vehicle? And when was it last serviced?

200k

Mechanic's Assistant: What is the model/year of your Mercedes?

Ml(###) ###-####

Mechanic's Assistant: Are you fixing your 430 yourself? What have you tried so far?

Yes, I have tried by pass relay and I could here the fule pump run when it is turn on

Mechanic's Assistant: Anything else you want the mechanic to know before I connect you?

I belive the relay is good and the voltage is good also

Submitted: 8 months ago.Category: Mercedes
Show More
Show Less
Ask Your Own Mercedes Question
Answered in 23 minutes by:
7/29/2017
Mercedes Mechanic: David Craig, Auto Mechanic replied 8 months ago
David Craig
David Craig, Auto Mechanic
Category: Mercedes
Satisfied Customers: 5,152
Experience: Owner/Mechanic at 3D Automotive
Verified

Hi Im David, thanks for visiting the site. you need to replace the filter and if that doesnt do it then your fuel pump is weak, replace it. thats way low.

Ask Your Own Mercedes Question
Customer reply replied 8 months ago
sorry the information that I put in was wrong, the actual pressure is 55 and the engine shout off after warm up
Mercedes Mechanic: David Craig, Auto Mechanic replied 8 months ago

ok, 55 is good. how long did it run before shutting off?

Ask Your Own Mercedes Question
Customer reply replied 8 months ago
about 30 minut on ideal
Mercedes Mechanic: David Craig, Auto Mechanic replied 8 months ago

ok, did you try to start it right back up?

Ask Your Own Mercedes Question
Customer reply replied 8 months ago
it not start. it crank but not fire up
Mercedes Mechanic: David Craig, Auto Mechanic replied 8 months ago

then it starts when cooled down correct?

Ask Your Own Mercedes Question
Customer reply replied 8 months ago
it took a while to cool down enough
Mercedes Mechanic: David Craig, Auto Mechanic replied 8 months ago

classic crankshaft position sensor thermal breakdown

Ask Your Own Mercedes Question
Customer reply replied 8 months ago
how could i confirm this? is there any way to test it?
Customer reply replied 8 months ago
I mean I don't even know where it is located. I would like to confirm it before tare everything in parts.
Mercedes Mechanic: David Craig, Auto Mechanic replied 8 months ago

sure give me a few to find the test

Ask Your Own Mercedes Question
Customer reply replied 8 months ago
thanks
Mercedes Mechanic: David Craig, Auto Mechanic replied 8 months ago

heres the location. it sits on top of the transmission where the tranny and engine meet. leave the connector on and back probe the connector while the engine is being cranked and check that it produces ac voltage

Ask Your Own Mercedes Question
Customer reply replied 8 months ago
thanks, ***** ***** it control ? fuel injector or spark plug or both?
Mercedes Mechanic: David Craig, Auto Mechanic replied 8 months ago

it controls rotation information to the computer to let the computer know the engine is rotating then the computer will command the injectors to pulse and the coils to fire

Ask Your Own Mercedes Question
Customer reply replied 8 months ago
whiche means the injector will not release fuel when the crankshaft position sensor bad?
Mercedes Mechanic: David Craig, Auto Mechanic replied 8 months ago

yes or when its overheated.

Ask Your Own Mercedes Question
Customer reply replied 8 months ago
but what could possibly cost it overheated?
Customer reply replied 8 months ago
looks like the most important is to find out the cause of the overheat.
Mercedes Mechanic: David Craig, Auto Mechanic replied 8 months ago

age, heat,

Ask Your Own Mercedes Question
Mercedes Mechanic: David Craig, Auto Mechanic replied 8 months ago

no thats not the most important thing, ignition components are subject to a lot of heat and over the years they start breaking down

Ask Your Own Mercedes Question
Customer reply replied 8 months ago
it would be OK if I put a new one ?
Customer reply replied 8 months ago
I am worry about it may fail again if I could not remove the cause of the overheat
Mercedes Mechanic: David Craig, Auto Mechanic replied 8 months ago

sure, replace it.

Ask Your Own Mercedes Question
Customer reply replied 8 months ago
would you also provide me the correct fuel pressure for this kind of car and how could I know which part cause the problem? fuel pump or regulater?
Mercedes Mechanic: David Craig, Auto Mechanic replied 8 months ago

I thought you said the pressure was 55 which is good

Ask Your Own Mercedes Question
Customer reply replied 8 months ago
would crankshaft position sensor controls fuel injector only or spark plug also?
I am trying to find a way to confirm that the position sensor is the problem
Customer reply replied 8 months ago
the fuel pressure is 55 for a while and I also noticed that the pressure could be very low sometimes
Customer reply replied 8 months ago
I have noticed that the fuel pressure kind of very low while the engine was cranking but not fire up
Mercedes Mechanic: David Craig, Auto Mechanic replied 8 months ago

ok, you are overthinking things, here. I will open this up o maybe someone else can explain it to you better. good luck

Ask Your Own Mercedes Question
Mercedes Mechanic: Wolfgang, Mercedes Technician replied 8 months ago
Wolfgang
Wolfgang, Mercedes Technician
Category: Mercedes
Satisfied Customers: 5,078
Experience: master tech benz ase cerified L1 and L2
Verified

Thanks for choosing Just Answer . I'm Wolfgang here to help!!

I am confident we can resolve your problem together. Please
understand that I don't know your skill level. In most cases when you have a problem
with the way the vehicle performs, specialized tooling is required to acquire computer
data/information or engine testing results. We didn’t build these complicated vehicles; we
just diagnose and fix them. Also understand that I can't see, smell, hear, or touch the
vehicle either, so it may take a few replies to get to satisfactory results. Note there may be an issue where the complexity of the issue will require a Premium Service. This service will be an addition to the normal question cost. Usually it does not come down to this but keep in mind!! I am also going to direct you with the fastest, easiest and most common things to check first. Please be
patient and permit me to do what I do best.
I also try to give all of the information you may need, expecting a “positive rating” in
return. I will also continue assisting you after you have rated me, if necessary. If there
is any reason I cannot get a positive rating, please let me know why “in advance”, so I
can go another direction for you. I am sorry you’re having this problem; I’ll help you
through it.
Below is my first answer or request for more information. If you do not understand it, or you need more information from me, or need me to go in more detail.

I do need the vin # to get the factory repair information to assist!!

Thanks

Ask Your Own Mercedes Question
Customer reply replied 8 months ago
1st thing that I need to know is the resistance reading of the fuel pump at the point the relay. I would do a few test today with complete report and contact you later. please let me know if you would like do some test for you to have a batter understanding, I would perform the test and give you the result today.
Mercedes Mechanic: Wolfgang, Mercedes Technician replied 8 months ago

the resistance reading would vary on electromechanical motors.

what is the exact issue of the vehicle? no start ? scan test performed?

thanks

Ask Your Own Mercedes Question
Customer reply replied 8 months ago
Where could I buy the scanner
Does it have one could attach to I phone?
Mercedes Mechanic: Wolfgang, Mercedes Technician replied 8 months ago

As i have asked what is the exact issue with the vehicle please.

If you can help me with what is going on i can help you in fixing.

Thanks

Ask Your Own Mercedes Question
Was this answer helpful?
Ask MB Paul Your Own Question
MB Paul
MB Paul
MB Paul, Mercedes Technician
Category: Mercedes
Satisfied Customers: 3,567
3,567 Satisfied Customers
Experience: Qualified Mercedes Benz Diagnostic Technician - 20+ years experience - Workshop Foreman for Mercedes

MB Paul is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry.

Stephanie PElm City, NC

used your service this weekend with "Trecers" help. thank you ,thank you, thank you. replaced an A/C fan motor. Local Auto Zone had part. $15.00 "tracer" fee and $40.00 for parts, I saved several hundreds of dollers at a shop. i will recommend you and use you in the future.

David L.Richmond, TX

9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much.

PhilMarysville, CA

Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible.

CharlesWalnut Creek, CA

As a single woman, I really appreciate an excellent and affordable opinion.
Thank you Geordie, I will not hesitate to contact justanswer in the future!

SueCharleston, WV

Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, Frank...you do indeed know your stuff.

JimCastleberry, FL

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

< Previous | Next >

Meet the Experts:

MB Paul

MB Paul

Mercedes Technician

3,567 satisfied customers

Qualified Mercedes Benz Diagnostic Technician - 20+ years experience - Workshop Foreman for Mercedes

Marty

Marty

Mercedes Technician

29,009 satisfied customers

Bosch Certified Master Tech. Over 35 years experience.

Lou P. master tech

Lou P. master tech

Mercedes Technician

3,771 satisfied customers

15 years master certified 100% fix rate and have access to factory radio codes, wiring, and instructions.

Michael Warfield

Michael Warfield

Factory Mercedes-Benz Technician

3,131 satisfied customers

Mercedes-Benz Master Certified technician

Matt

Matt

Engineer

602 satisfied customers

Mechanical Engineer with 23 years experience in the auto industry, 8 yrs in formula 1 engine testing

promerc

promerc

mercedes diagnostic technician

553 satisfied customers

Qualified mercedes diagnostic technician & service team manager , ATA registered Master tech

Hipo64

Hipo64

Mercedes Technician

444 satisfied customers

Work and diagnose electronics on daily basis.

< Previous | Next >

Related Mercedes Questions
Changed out the Spark Plugs on my 1999 SL 500 AMG first the
Changed out the Spark Plugs on my 1999 SL 500 AMG first the left side. Car ran great. Next day the Right side, now the car Idles rough, Stalls and when you give it gas it bogs down no power … read more
Lou P. master tech
Lou P. master tech
Mercedes Technician
Bachelor's Degree
3,771 satisfied customers
Random misfire from 1 2 3 and 4 changed all spark plugs and
random misfire from 1 2 3 and 4 changed all spark plugs and coils still same codes no injector pulse from those cylinders … read more
Wolfgang
Wolfgang
Mercedes Technician
5,078 satisfied customers
2007 s550, had transmission. Had transmission fluid changed
Had transmission fluid changed 2 weeks ago at 143000 miles. No problem before then. Now transmission has hard gear change in lower gear and slips , can hear a whirring sound at gear change when it slips. … read more
eauto
eauto
self employed
High School or GED
74 satisfied customers
Misfiring 0n sparks 5 and 6. Replaced spark plugs, wires,
Misfiring 0n sparks 5 and 6. Replaced spark plugs, wires, coils, and position sensor and still getting misfire … read more
Gary
Gary
Senior Technician
Vocational, Technical or Trade School
89 satisfied customers
I just bought a 2007 SL550 and the transmission is slipping
I just bought a 2007 SL550 and the transmission is slipping out of gear. Turned it off and the problem goes away. It has. 62000 on the clock. Seems there are ideas to change a valve to replace the tra… read more
Marty
Marty
Mercedes Technician
Associate Degree
29,009 satisfied customers
I just replaced my spark plug wires and after I replaced
I just replaced my spark plug wires and after I replaced them my car started with a rough idle and when I gave it gas it just dies it ran fine before I touched it … read more
Lou P. master tech
Lou P. master tech
Mercedes Technician
Bachelor's Degree
3,771 satisfied customers
I was changing the spark plugs on a1999 c230,,and the wire
I was changing the spark plugs on a1999 c230,,and the wire connector that connects to the coil pack broke,,could I splice the wire and use another connector … read more
BOBBYSS
BOBBYSS
TECHNICIAN/ADVISOR
Associate Degree
8,343 satisfied customers
Costs to replace 8 spark plugs, clean all fuel injectors,
Costs to replace 8 spark plugs, clean all fuel injectors, replace left and right valve cover gaskets, replace tensioner on timing chain. … read more
Marty
Marty
Mercedes Technician
Associate Degree
29,009 satisfied customers
1985 SL380 cranks no start. Sl380. New spark plugs, wires,
yes, new spark plugs, wires, cap rotors, new fuel filter injectors, fuel pump, regulators, thermo time switch, modulator valve … read more
Marty
Marty
Mercedes Technician
Associate Degree
29,009 satisfied customers
1988 300e no power to coil. None. Pulling spark plugs.12
1988 300e no power to coil JA: Is the power loss consistent, or does it fluctuate? Customer: none JA: Are you fixing your 300E yourself? What have you tried so far? Customer: pulling spark plugs.12 te… read more
Marty
Marty
Mercedes Technician
Associate Degree
29,009 satisfied customers
Spark plug gap? Smart Passion 2014. Am ready to install new
yes, am ready to install new plugs but need to verify plug gap … read more
Kevin
Kevin
workshop foreman /master tech/mot tester
1 satisfied customers
What is the spark plug gap for a 79 450SL, I put in all new
I put in all new injectors and sleeves plus rebuilt the fuel distribution block and now it won't fire.… read more
fordguy4u
fordguy4u
Automotive Tech
Vocational, Technical or Trade Scho
70 satisfied customers
I changed the spark plugs on my 04 C240 and after doing so
Hello , I changed the spark plugs on my 04 C240 and after doing so the car had no power. I checked for spark at each plug, witch it had. then i replaced the plugs with a new set. … read more
heavy_chevy_396
heavy_chevy_396
Vocational, Technical or Trade Scho
2,518 satisfied customers
Lou should I replaced spark plugs while valve covers off?
Lou should I replaced spark plugs while valve covers off? Because I wanna blow first deep inside… read more
Lou P. master tech
Lou P. master tech
Mercedes Technician
Bachelor's Degree
3,771 satisfied customers
Hard start. 1989 SE300. Change spark plugs ,distributer
Yes ,change spark plugs ,distributer cap,router ,plugs wire … read more
Curtis
Curtis
Vocational, Technical or Trade Scho
1,697 satisfied customers
Just changed spark plugs and coils still not right under
Just changed spark plugs and coils still not right under load not firing under load. … read more
BOBBYSS
BOBBYSS
TECHNICIAN/ADVISOR
Associate Degree
8,343 satisfied customers
Pete would you recommend this spark plugs for m113 engine?
Pete would you recommend this spark plugs for m113 engine? https://www.amazon.com/NGK-Iridium-Spark-Plugs-7397/dp/B0033HZQUG/ref=sr_1_3?ie=UTF8&qid=1501108640&sr=8-3&keywords=NGK+IridiumsOr which is b… read more
Wolfgang
Wolfgang
Mercedes Technician
5,078 satisfied customers
ATTN ..ONLY for LOU P Lou what is correct spark plugs for
ATTN ..ONLY for LOU PLou what is correct spark plugs for M113 engine? And do you have a manual ?… read more
Lou P. master tech
Lou P. master tech
Mercedes Technician
Bachelor's Degree
3,771 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x